Vehicle stability control system and method

• US 8,532,906 B2
• Filed: 02/08/2012
• Issued: 09/10/2013
• Est. Priority Date: 01/23/2008
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Lu, Jianbo, Johnson, Leonard K., Meyers, Joseph Carr
• Primary Examiner(s): Tran, Khoi
• Assistant Examiner(s): Nguyen, Bao Long T
• Application Number:
  US13/368,875
• Publication Number:
  US 20120209490A1
• Time in Patent Office: 580 Days
• Field of Search: None
• US Class Current: 701/94
• CPC Class Codes: B60K 31/00 Vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed, i.e. preventing speed from exceeding an arbitrarily established velocity or maintaining speed at a particular velocity, as selected by the vehicle operator fittings acting on two or more sub-units B60W30/14; speedometers G01P; systems or devices for controlling speed in general G05D13/00 ; in traffic anti-collision system for road vehicles G08G1/16
• CPC Class Codes: B60T 2201/04 Hill descent control
• CPC Class Codes: B60T 2201/06 Hill holder; Start aid systems on inclined road
• CPC Class Codes: B60T 2230/02 Side slip angle, attitude angle, floating angle, drift angle
• CPC Class Codes: B60T 7/12 for automatic initiation; for initiation not subject to will of driver or passenger limiting speed of vehicles other than rail vehicles B60K31/00
• CPC Class Codes: B60T 7/122 for locking of reverse movement
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60T 8/17551 determining control parameters related to vehicle stability used in the regulation, e.g. by calculations involving measured or detected parameters
• CPC Class Codes: B60T 8/17552 responsive to the tire sideslip angle or the vehicle body slip angle
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 2510/0225 Clutch actuator position
• CPC Class Codes: B60W 2510/0604 Throttle position
• CPC Class Codes: B60W 2510/1005 Transmission ratio engaged
• CPC Class Codes: B60W 2510/186 Status of parking brakes
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2540/12 : Brake pedal position
• CPC Class Codes: B60W 2552/15 : Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2710/0677 : Engine power
• CPC Class Codes: B60W 30/18118 : Hill holding

Abstract

A vehicle stability control system comprises a 5-sensor cluster and a stability controller configured to communicate with the 5-sensor cluster and receive signals corresponding to a lateral acceleration, a longitudinal acceleration, a yaw rate, a roll rate, and a pitch rate from the 5-sensor cluster. The stability controller can also be configured to determine a braking amount or a throttle amount to maintain vehicle stability. The system also comprises a brake controller configured to communicate with the stability controller and receive a braking request from the stability controller, and a throttle controller configured to communicate with the stability controller and receive a throttle request from the stability controller. The system may also comprise a braking or throttling command computed based on various scenarios detected by measured and calculated signals.

Claims

1. A method for maintaining a driver'"'"'s selected speed of a vehicle during hill driving, the method comprising:

receiving signals corresponding to a lateral acceleration, a longitudinal acceleration, a yaw rate, a roll rate, and a pitch rate with a stability controller;

calculating a vehicle pitch angle from the lateral acceleration, the longitudinal acceleration, the yaw rate, the roll rate, and the pitch rate with the stability controller;

calculating a longitudinal velocity gradient from the vehicle pitch angle with the stability controller;

determining whether the longitudinal velocity gradient is substantially close to zero with the stability controller; and

issuing a signal from the stability controller to change a throttle input of the vehicle to change the vehicle'"'"'s velocity if the longitudinal velocity gradient is not substantially close to zero.

2. The method of claim 1, further comprising applying brakes of the vehicle to change the vehicle'"'"'s velocity if the longitudinal velocity gradient is not substantially the same as a driver'"'"'s selected value.

3. The method of claim 1, wherein the signals corresponding to the lateral acceleration, the longitudinal acceleration, the yaw rate, the roll rate, and the pitch rate are received from a 5-sensor cluster.

4. A method for maintaining a constant speed for a vehicle, the method comprising:

receiving signals corresponding to a lateral acceleration, a longitudinal acceleration, a yaw rate, a roll rate, and a pitch rate with a stability controller;

calculating a vehicle pitch angle from the lateral acceleration, the longitudinal acceleration, the yaw rate, the roll rate, and the pitch rate with the stability controller;

calculating a longitudinal velocity gradient from the vehicle pitch angle with the stability controller; and

maintaining the longitudinal velocity gradient substantially at zero via signals issued from the stability controller.

5. The method of claim 4, wherein the longitudinal velocity gradient is maintained substantially at zero by changing a throttle input of the vehicle.

6. The method of claim 4, wherein the longitudinal velocity gradient is maintained substantially at zero by applying brakes of the vehicle.

7. The method of claim 4, wherein the signals corresponding to the lateral acceleration, the longitudinal acceleration, the yaw rate, the roll rate, and the pitch rate are received from a 5-sensor cluster.

8. The method of claim 4, wherein the maintaining the longitudinal velocity gradient includes maintaining a vehicle speed substantially at zero for hill hold control.

9. The method of claim 8, wherein the receiving includes receiving a clutch status for a manual transmission to detect backward rolling of the vehicle.

10. The method of claim 8, wherein the receiving includes receiving a signal from one or more wheel speed sensors to detect backward rolling of the vehicle.

11. A method for maintaining a driver'"'"'s selected speed of a vehicle during hill driving, the method comprising:

receiving signals corresponding to a lateral velocity, a longitudinal acceleration, a longitudinal velocity, a yaw rate, with a stability controller;

calculating a vehicle pitch angle from the longitudinal acceleration, a time derivative of the longitudinal velocity, the yaw rate, and the lateral velocity with the stability controller;

calculating a longitudinal velocity gradient from the longitudinal acceleration and the vehicle pitch angle with the stability controller;

determining whether the longitudinal velocity gradient is substantially close to zero with the stability controller; and

issuing a signal from the stability controller to change a throttle input of the vehicle to change the vehicle'"'"'s velocity if the longitudinal velocity gradient is not substantially close to zero.

12. The method of claim 11, wherein the longitudinal velocity gradient is maintained substantially at zero by changing a throttle input of the vehicle.

13. The method of claim 11, wherein the longitudinal velocity gradient is maintained substantially at zero by applying brakes of the vehicle.